Sidestep Kernel with RDMA

Remote Direct Memory Access - or RDMA for short - allows machines to access memory of other machines without going through the operating system kernel.  

This is a traditional computer science trick - if you have an abstraction in the way of your objective, bypass the abstraction.

The idea is to get performance improvement - low latency and high throughput. Sometimes these tricks come under the label of "ultra-low-latency software development" or "ultra low latency techniques".

The goal is zero-copy (or near-zero-copy) data transfer - data moves between memory buffers directly. 

Key benefits include:

• Skipping kernel involvement
• Avoid creation of multiple intermediate copies
• Avoid switching between kernel space and user space

Protocols to support this include:

• InfiniBand
• RoCE (RDMA over Converged Ethernet)
• iWARP (RDMA over TCP/IP).

Protocols need to be supported at the OS level. Microsoft Windows Server 2012 onwards for example support iWARP.

From Windows Server 2019 to Windows Server 2022

Windows Server 2022 is now in preview and is planned for release later in 2021. See this article from the Windows Server team. Note that one of the conditions of use is that you do not use a preview server in a production environment. 

The new 2022 Server brings some Azure innovations on-premise.  

This includes Azure Arc which aims at simplified management of hybrid and multi-cloud environments as well as Storage Migration Service which makes it easy to migrate data from older Windows Server installations to Azure or Windows Server 2019/2022.

The secured-core server is key to WS2022 design. This is a response to the rise in cyberattacks on servers targeted for ransomware attacks or bitcoin mining for example.

Firmware protection is one dimension of the security of the new design. There is evidence that ransomware platforms are adding firmware exploitation capabilities.  There have been attacks e.g. on Active Directory Domain Controllers. DMA protection is one of the defence mechanisms utilized.

Virtualization based security (VBS) is one of the pillars of the secure-core server design. Features  included such as Hypervisor-Protected Code Integrity (HVCI) - also part of Windows 10 (which has some known issues with device drivers).